Process for obtaining textile end products using discontinuous fibers



Aug. 6, 1963 M. MASUREL ETAL 3,099,907

PROCESS FOR OBTAINING TEXTILE END PRODUCTS USING DISCONTINUOUS FIBERSFiled Dec. 4, 1961 2 Sheets-Sheet l A TTO/FNEKS Aug. 6, 1963 M. MASURELETAL 3,099,907

PROCESS FOR OBTAINING TEXTILE END PRODUCTS USING DISCONTINUOUS FIBERSFiled Dec. 4, 1961 2 Sheets-Sheet 2 g- 4 INVEN TOPS A TT'ORNEYS UnitedStates Patent Claims priority, application Great Britain Dec. 8, 1960 7Claims. (Cl. 57-156) Hitherto in order to obtain from discontinuousfibers textile products ready for use, termed generally end products,such as knitted wear and fabrics, there was used as the startingmaterial yarn spun on continuous spinning frames, "or much more rarelyon spinning mules.

The only exceptions to this general practice are nonwoven fabrics; forexample felts or hinder impregnated card webs.

The conventional procedure is as follows:

To obtain the yarn one starts from a sliver or roving of discontinuousfibres obtained from the last spinning stage (finishers or rovingframes) and this sliver or roving is subjected in the order set outbelow to the following processes which are independent of each other andare carried out on separate machines.

First of all the silver or roving is drawn by a drawing process in orderto thin it and bring it down to the required fineness or count for theyarn to be obtained. It is then twisted to give strength to the yarn andat the same time the yarn thus obtained is wound onto a bobbin.

This work is carried out either in a continuous manner (continuousspinning frame) or in a discontinuous manner (mule), the operations ofdrawing and twisting then being separate from the mule windingoperations.

The yarn thus obtained by continuous spinning is then taken up bybobbins in an amount limited by weight (generally 100 to 200 grams ofyarn per bobbin). It is then generally rewound on winding machines whichpermit the yarn to be supplied on large bobbins, generally conical inform (normally weighing l-Z kilograms) so that it can then be used at abetter production rate on the make-up machines.

The customary procedures may also provide for a certain number ofancillary operations such as retwisting (uptwisting or downtwisting) ordoubling which consists in twisting together the single threads obtainedon spinning frames in order to give them greater strength and betterappearance.

It is the large bobbins aforesaid that are used for the manufacture ofend products ready for use such as knitted wear, fabrics, etc.

This customary procedure possesses the following main disadvantages:slow speed of the continuous spinning frame and the impossibility ofguaranteeing continuity of various operations, i.e. their completeautomation.

In particular it is known that the speed of the spinning frame islimited by the following factors:

To ensure strength in the sliver or roving obtained after drawing, it ispermanently twisted, i.e. in such a manner that the yarn obtainedretains its degree of twist permanently, even after the winding.

For this purpose the fine sliver or roving coming from the rolling unitis passed through a traveller displaceable on a ring and is wound by avertical spindle, rotating at a great speed, which by virtue of thepresence of the traveller imparts torsion to the thread while windingit.

The rate of production of the yarn is limited by the high rate oftorsion, or rather by factors which are closely related therewith:

Speed of rotation of the spindle (of the *order of 10,000 r.p.m.)limited by the weight of the bobbin;

3,099,907 Patented Aug. 6, 1963 Speed of displacement of the travellerwhich depends on the rotation of the spindle and high rate of torsion tobe given to the yarn, but which is limited to 32-35 metres per secondfor technical reasons: undue heating of the metal of the traveller.

Generally the speed of the yarn, and thereby its production is thuslimited to 2025 metres/minutes at the maximum.

The low rate of production of yarn by continuous spindle spinningmachines which is thus occasioned has as a consequence that the quantityof yarn produced is too small for an extensive captial investment.

At [this stage it may be pointed out that uptwisting machines forcontinuous yarns (silk or man-made fibres) which do not need apreliminary drawing eliminate the bobbin, obviously cutting out thedisadvantages of the traveller by rotating the feed bobbin instead ofthe receiver traveller, but still retaining the disadvantages due to thelimitations on the speed of the spindle.

There should also be noted the permanent twist devices which apply theprinciple of the hollow spindle and double twist. These devices are onlyjust coming into use commercially and are complicated and costly.

' It has also been proposed to overcome the costliness of the operationof continuous spinning by one of the devices mentioned above, byreplacement of a spinning operation without twist called false twist.

Following this known method the thinned sliver or roving brought down tothe required size for the yarn to be made, passes through a device suchas a rotating disc with an eccentric hole through which the yarn beingformed passes, Without a subsequent winding device, and which twists thesliver or roving while transforming it into yarn, but only in atemporary manner.

This operation is currently described as false twist; in this case thetwist thus applied is only temporary and the yarn tends to return to thesliver state, so that the twist has to be retained by impregnating thefibres making 'up the yarn with a binder.

'by the convention process, by rendering the false twist permanent andalso increasing the resistance to breakage of the fine sliver as it isbeing formed into a thread.

This known process where true twist is replaced by false twist madepermanent by means of a binder, re-

quires as in the conventional process, winding of the yarn obtained andits use at a later stage on a machine for making end products ready foruse. The speed of false twist operation is not limited by the sametechnical conditions as that of true twist by the traveller but it doesgenerally call for a drying process for the yarn to which the binder hasbeen applied in the wet state.

Since the rate of feed of the yarn is high, these drying operations area delicate process if a perfectly dry yarn is to be obtained, operatingcosts are thus being increased while at the same time losing some of theadvantages of the high production speed (of the order of metres/minute).

The presence of a binder in the yarn tends moreover to limit its fieldof application, since the yarn no longer has a fibrous touch and lacksflexibility.

3 manent, the yarn to which this provisional twist is applied being useddirectly in the machine for manufacturing the end product.

By reason of this immediate usage, the provisional twist is retainedlong enough for the manufacture of the end product, and it is theretention of the fibres within the end product which afterwards.maintains the cohesion of the yarn reverting to a fine sliver and avariable fraction of the twist.

This twist retention is achieved by means of the tying made by themachine: stitches and overlapping in the case of knitting machines,tying of the warp and of the weft by simple crossing as on a weavingloom, or even eventually tying by chain stitches.

It will be noted here that the term provisional twist has been usedrather than .the term false twist. In eifect the term false twist isnormally applied not only to the present case and that previouslyrecalled, where the yarn is mobile, i.e. displaces itself all the waythrough the device applying the false twist, but also in the case wherethe yarn is immobilised at both ends. Thus when the yarn is fixed, thefalse twist is permanent, while in the present case it is onlyprovisional, as pointed out in the case of the known process, implyingthereby the use of a binder for the manufacture of this twist.

As has been explained this process gives the advantage that theprovisional twist device permits much greater speeds to be attained (itbeing possible to attain, if needed, many tens of thousands of rpm.) andin any case to supply yarn with provisional twist at a speed .at leastequal to the feeding speed of the most speedy knitting and weavingmachines. Consequently sucha machine can be directly fed from a drawinghead and provisional twist device, without the intermediary of thecustomary spindles for the finished yarn and the feed bobbins for themake-up machine, with a much cheaper apparatus and with a considerablesaving of time.

In addition, contrary to what .one would at first expect, the quality ofthe end product, far from being inferior, is found to be improved.

The end product has a much more even appearance; the provisional twistevens out the arrangement of the fibres, so that in the case of amixture of fibres of differing colours, the product presents a moreuniform colour.

The product has less defects in view of the absence of knots whichcommonly arise at the ends of the yarn on each bobbin.

In addition, there are practically no yarn breakages as has been pointedout above. In any case, the provisional twist twists the fibresimmediately as they come from the drawing device, and since the rate oftwist is not limited, .the strength of the yarn can be sufiicient toprevent any breakage and to trap any floating fibres, which is notalways the case in conventional continuous spinning.

Finally the end product has a very much better feel, since the fibresare no longer twisted and have not been impregnated with any chemicalagent before use on the make-up machine, unless this is donedeliberately for special purposes.

Other objects, features and advantages of the invention will be apparentfrom the following specification, when taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a schematic sectional view and illustrates an apparatusconstructed and assembled in accordance with the teachings of thepresent invention;

FIG. 2 is a schematic plan view of the apparatus illustrated in FIG. 1;

FIG. 3 is a view similar to FIG. 1 illustrating a second embodiment ofthe invention; and

FIG. 4 is a schematic plan view similar to FIG. 1 but illustrating theembodiment of FIG. 3.

The apparatus shown in FIGURES 1 and 2 comprises for each thread or yarnto be supplied to the make-up machine 1 (knitting machine or loom) adrawing device on conventional lines as indicated generally by thenumeral 2 and a temporary twist device. This twist device can, forinstance, be made up of a disc or pulley 3 rotating about an axis 4disposed in an extension of the drawing frame and pierced with aneccentric hole 5, through which pass the fibres 6 as they come from thedrawing frame, whereby these are temporarily twisted, as at 7. In amodification the fibres may be passed around the periphery of arubber-covered cone (not shown).

The disc may rotate in a continuous or intermittent manner in one orother direction but always giving a temporary twist which completely orpartly disappears when the yarn is made up in the make-up machine.

The speed of rotation and thereby the twisting speed of this device iscorrelated with the feed speed of the yarn. When the drawing devicestops the twisting device must also stop.

The make-up machine 1 can be 'of any type so long as it ensures thetying of a thread with other threads to make up a product ready for use.For illustrative purposes this rcan be for example, a knitting machineof any type: rectilinear knitting machines (including full-fashionedknitting machines), knitting machines, tricot machines (includingRaschel machines). In such cases the tying is ensured by the interlacingof the stitches.

A loom in which the tying is ensured in the normal manner by thecrossing of the warp threads with the weft threads and/ or according toa new method of chainstitches for tying together the warp threads or theweft threads, or solely the warp threads.

It will be noted that the apparatus which has just been described formsin actual fact a single machine, comprising as many drawing devices andat least as many temporary twist devices as there are threads fed intothe make-up machine. It is characterised in that the speed of yarns orthreads as they leave the drawing frame must be the same as their feedspeed to the make-up machine.

On the other hand the threads enter the makeup machine continuously :orintermittently according to the type of machine. In the latter case thedrawing and temporary twist devices also work intermittently.

The embodiment illustrated in FIGURES 3 and 4, illustrates amodification wherein it is possible to .bring together sliver fibres NNissuing from the double drawing device which have already beenseparately twisted .in the same direction or in opposite directions bytwo temporary twist devices 3 and 3'; the threads 6-6 are then twistedin a second false twist device '8 (identical or not to the precedingones) but common to the temporary thread twist device 6 and 6. Thus itvw'll be seen that when twist devices 3 and .3 are rotated in the samedirection, a temporary twist in the same direction Will be imparted toall of the threads and that when the twist devices 3 and 3 are rotatedinopposite directions, one-half of the threads will have imparted theretoa temporary twist in one direction and the other of the threads atemporary twist in the other direction. The twist device 8 may berotated in either direction to obtain with the twist devices 3 land 3'the desired results in the end product.

In such a case one obtains a finished article 7a with threads showingseveral plies or ends and not made up of a single thread. This allowsthe elimination of twist or doubling operations in separate machines.

.Another modification consists in using a single yarn or ends obtainedfrom a little tow of continuous yarn which has been broken.

In this case the feed slivers are no longer discontinuous slivers, butlittle tows of continuous yarn or filament which are broken up intodiscontinuous fibres through tensioning and cracking during thestretching in a special drawing device 2.

A compound thread can also be used, either single or multi-endedobtained from slivers of discontinuous fibres and one or more continuousthreads, textured or otherwise. The continuous threads are then feddirectly to the take-off cylinders of the drawing frame but withoutgoing via the feed cylinder and stretching device.

The following examples are given which, however, are to be regarded asnon-limiting.

Example 1 A sliver of wool of metric number 0.7 (or 700 metres to thekilogram) is employed which is prepared for use in the mechanismsrepresented by the FIGURES l and 2. This sliver is drawn by the feedrolls of the drawing frame which subjects it to a drawing rate of 20. Inthis manner it is delivered by the delivery rolls of the said drawingframe with a metric number of 14. The speed of the delivery rolls is inthe neighbourhood of 50 metres a minute whereas that of the feed rollsis of 50/20 metres a minute that is in the neighbourhood of 2.50 metresa minute. This sliver -fined to number 14, is temporarily twisted by atemporary twisting apparatus for example an eccentric hole in a pulleyturning at 5000 rpm. Thus this sliver becomes a temporarily twistedthread of number 14 which is fed directly into a circular machine ofdiameter of 94 millimetres, of gauge 9 corresponding to the drawinggauge of the thread employed.

This machine seen on small scale only uses the thread at a speed ofabout 50 m./minute equal to the speed of the delivery rolls of thedrawing frame. Thus knitwear is obtained where the simple threademployed loses little by little its twist according to the rate ofknitting. This allows knitwear to be obtained with a soft touch and ofgreat evenness.

Example 2 Two wool slivers of metric number 1.4 (or 1.4 kilometres tothe kilogram) are employed which are caused to enter in the mechanismrepresented by the FIGURES 3 and 4. These two slivers are drawnseparately by the feed rolls of the drawing frame which submits them forexample to a drawing rate of 20. These slivers are delivered by thedelivery rolls with a metric number of 28. The speed of the deliveryrolls is about 70 metres/minute whereas that of the feed rolls is of 70/20 millimetres a minute that is about 3 .50 metres/ minute.

These two slivers fined to number 28 are temporarily twisted separatelyin the same direction or in opposite directions in the temporarytwisting apparatus 3 and 3' turning at 6000 rpm.

Thus they become temporarily twisted threads of number 28 which arejoined side by side in a temporary twisting apparatus 8 common to thetwo threads turning at 3000 rpm. When the twisting apparatus 3 and 3'are turning in the same direction, twisting apparatus 8 is generallyturning in the reverse direction. Thus there is obtained a temporarytwisted and re-twisted thread of drawing number 2/28=14 which is feddirectly to the circular machine of 94 millimetres and of gauge 9corresponding to the draw of thread utilised.

The speed of utilisation of the thread in the knitting machine is about70 metres a minute equal to the speed of the delivery rolls.

The knitting obtained has a good touch because the temporary twistedthread loses little by little its twist at the rate at which it isknitted and has a greater even- 6 ness in appearance (because use ismade of twisted thread).

What we claim is:

1. A process for manufacturing textile end products in a make-up machinecomprising the steps of drawing slivers of discontinuous fibres intothreads of the fineness of said end product, imparting a temporary twistto said threads, feeding said temporary twisted threads directly to themake-up machine, forming said threads into said end product in saidmake-up machine while permitting said temporary twisted threads tountwist, and recovering said end product from said make-up machine.

:2. A process as in claim 1 in which the temporary twist is applied bypassing the thread through an eccentric hole moving in a rotating path.

3. A process as in claim 1 in which said temporary twisted threadsretain a variable fraction of said temporary twist in said end product.

4. A process as in claim 1 in which said temporary twisted threadsrevert to substantially completely untwisted threads in said endproduct.

5. A process for manufacturing textile end products in a make-up machinecomprising the steps of drawing slivers of discontinuous fibres intothreads of the fineness of said end product, imparting a temporary twistto said threads, joining said temporary twisted threads into pairsdisposed in side by side relationship, imparting a temporary twist tosaid pairs of threads to form a temporary twisted assembly, feeding saidtemporary twisted assembly directly to the make-up machine, forming saidtemporary twisted assemblies of pairs of threads into said end productin said make-up machine while permitting said temporary twisted threadsto untwist, and recovering said end product from said make-up machine.

6. A process as in claim 5 in which said temporary twist imparted tosaid threads is in one direction and said temporary twist imparted tosaid temporary twisted assemblies of pairs of threads is in the oppositedirection.

7. A process for manufacturing textile end products in a make-up machinecomprising the steps of drawing slivers of discontinuous fibres intothreads of the fineness of the end product, imparting a temporary twistto onehalf of said threads in one direction and to the other half ofsaid threads in the other direction, joining oppositely twisted threadsinto pairs disposed in side by side relationship, imparting a temporarytwist to each of said pairs of threads to form a temporary twistedassembly, feeding said temporary twisted assemblies of pairs of threadsdirectly to the make-up machine, forming said temporary twisted threadsinto said end product in said make-up machine while permitting saidtemporary twisted threads to untwist, and recovering said end productfrom said make-up machine.

References Cited in the file of this patent UNITED STATES PATENTS760,619 Fredenburgh May 24, 1904 819,298 Martin May 1, 1906 1,953,368Spring Apr. 3, 1934 2,373,091 Astley Apr. '10, 1945 2,807,130 Trapido etal. Sept. 24, 1957 2,921,455 Furge Jan. 19, 1960 FOREIGN PATENTS 253,415Great Britain June17, 1926

1. A PROCESS FOR MANUFACTURING TEXTILE END PRODUCTS IN A MAKE-UP MACHINECOMPRISING THE STEPS OF DRAWING SLIVERS OF DISCONTINUOUS FIBRES INTOTHREADS OF THE FINENESS OF SAID END PRODUCT, IMPARTING A TEMPORARY TWISTTO SAID THREADS, FEEDING SAID TEMPORARY TWISTED THREADS DIRECTLY TO THEMAKE-UP MACHINE, FORMING SAID THREADS INTO SAID END PRODUCT IN SAIDMAKE-UP MACHINE WHILE PERMITTING SAID TEMPORARY TWISTED THREADS TOUNTWIST, AND RECOVERING SAID END PRODUCT FROM SAID MAKE-UP MACHINE.